UMBELLIFER.E. (PARSLEY FAMILY.) 



189 



20. Cicuta. Flowers white. Fruit subglobose, twin: the carpels strongly and equally 5- 



ribbed. Leaves twice or thrice ternate. 



21. Sium. Flowers white. Fruit ovate or globular : the carpels 5-ribbed. Leaves all simply 



pinnate. 



22. Cryptotsenia. Flowers white. Fruit oblong. Leaves 3-parted. Umbel irregular. 



II. Inner face of the seed hollowed out lengthwise, or the margins invo- 

 lute, so that the cross-section is semilunar. (Umbels compound.) 



23. Chrerophyllum. Fruit linear or oblong, narrowed or beaked at the apex. 



24. Osmorrhiza. Fruit linear-club-shaped, tapering below : ribs bristly. 



25. Conium. Fruit ovate, flattened at the sides -. ribs prominent, wavy. 



26. Euloplius. Fruit ovoid, somewhat twin, nearly destitute of ribs. 



III. Inner face of the seed hollowed in the middle, or curved inwards at 

 the top and bottom, so that the section lengthwise is semilunar. 



27. Erigenia. Fruit twin : carpels nearly kidney -form. Umbellets few-flowered. 



1. HYDROCOTYLE, Tourn. Water Pennywort. 



Calyx-teeth obsolete. Fruit flattened laterally, orbicular or shield-sl 

 the carpels 5-ribbed, two of the ribs enlarged and often forming a thickened 

 margin : oil-tubes none. — Low, mostly smooth, marsh or aquatic perennials, 

 with slender creeping stems, and round shield-shaped or kidney-form leaves, 

 with scale-like stipules. FloAvers small, white, in simple umbels or clusters, 

 which are either single or proliferous, appearing all summer. (Name from 

 v8a>p 1 water, and kotvXyj, a flat cup, the peltate leaves of several species being 

 somewhat cup-shaped.) 



* Peduncles much shorter than the petioles : pedicels short or none : leaves not peltate. 



1. H. repanda, Pers. Petioles (2' -9' long) and peduncles (1'- 2' long) 

 clustered on the creeping stems or runners ; leaves ovate-heart-shaped with a shal- 

 low open sinus, repand-toothed, thickish ; flowers 2 - 4 in a head or cluster, with 

 a conspicuous 2-leavecl involucre ; ripe fruit ribbed, reticulated between the 

 ribs. — Maryland ( W. M. Canby) and southward. — Probably a variety of 

 H. Asiatica, L. 



2. H. ranunculoides, L. Petioles (2' -9' long) and peduncles (|'-I' 

 long, in fruit reflexed) from long commonly floating creeping stems ; leaves or- 

 bicular or kidney-form, 3 - 1 -cleft, the lobes broad and crenate ; flowers 5 - 1 in a 

 capitate umbel; fruit smooth, scarcely ribbed. — Pennsylvania to Virginia, and 

 southward. 



3. H. Americana, L. Stems filiform, branching, spreading and creeping ; 

 leaves rounded kidney-form, crenate-lobed and the lobes crenate, thin, very smooth and 

 shining, short-petioled ; the few-flowered umbels of minute flowers in their axils 

 almost sessile. — Shady damp places : common northward. 



* * Peduncles scape-like,- as long as the slender petioles, all from slender runners or 



rootstocks creeping in the mud: leaves orbicular, centrally peltate, simply or doubly 

 crenate : fruit sharp-margined. 



4. H. limbellata, L. Umbel many-flowered and simple or sometimes 

 proliferous (2 or 3, above one another) ; pedicels slender i£"-3" long); fruit 



